>>> h1
# header

<<<
<h1>header</h1>
>>> h2
## header

<<<
<h2>header</h2>
>>> h3
### header

<<<
<h3>header</h3>
>>> h4
#### header

<<<
<h4>header</h4>
>>> h5
##### header

<<<
<h5>header</h5>
>>> h6
###### header

<<<
<h6>header</h6>
>>> trailing "#" are removed
# header ######

<<<
<h1>header</h1>
